Sorcerous Origin - Bloodmage
Some sorcerers gain their power through their heritage, descendants of powerful beings with powers mere mortals cannot understand... Other sorcerers have their power through the unexplainable ways of the universe, but You have your powers through your own blood. Your blood carries a rare magical power you have learnt to unlock.
Power in the blood
Starting at 1st level, you start noticing that your health is somehow magically enhanced. Every time you take a level in this class your hitpoint maximum increases by 3.
Starting at 6th level you begin to understand the strange potential of your blood. During short rests you can spend your hit dice to regain spell slots. 1 hit dice equals one level of spell slot. A 3rd level slot needs 3 hit dice for example. The hit dice cannot be used for healing, and it's expended like it was used for healing.
Greater Blood Magic
Starting at 14th level, you gain the ability to empower your spells with your own blood as well as with sorcery points. By sacrificing 1d6 health for each sorcery points it would cost, you can add any one metamagic you know to the spell additionally to the original metamagic. The damage taken is necrotic damage
Expert Blood Magic
Starting at 18th level, you gain the ability to push your body to gain unbelievable power. You can cause a spell to do maximum damage by taking 1d6 necrotic damage per spell level.Cantrips cannot be empowered this way.